Ken, how do you expect to see the mirrors and your eyeball if you are at the base of the t'scope? You put the cheshire into the focuser tube, you look thru the 2mm hole in the top of the cheshire. Then you shine a torch,RED LED, into the large hole in the side. This illuminates the mirrors so that you can see where your eye is. If it ain't in the centre of the dartboard (concentric circles), then your t'scope ain't collimated!(with a little bit of 2ndary offset). Check this link.
http://skyandtelescope.com/printable...rticle_790.asp